As the demand increases for varying types of applications within mobile telecommunications networks, service providers must constantly upgrade their systems in order to reliably provide this expanded functionality. What was once a system designed solely for voice communications has recently grown into a heterogeneous system that enables access to communications platforms such as text messaging, multimedia streaming along with general Internet access. To support such applications, service and infrastructure providers have built new networks over existing voice communication infrastructure. While this has enabled added functionality without appreciable service interruptions, such makeshift modifications have served as less-than-ideal long-term solutions for a communications infrastructure. As evidenced by second and third generation networks, voice services must be carried over dedicated voice channels toward a traditional circuit-switched core, while other services, such as IP-enabled data and communications may be transmitted over a different packet-switched core, following Internet protocol (IP). This has led to unique problems, including, for example, application provision, metering and charging, and quality of experience (QoE) assurance.
One recent attempt to enhance the dual-core approach of the second (2G, 2.5G) and third generations (3G) of mobile telecommunications standards defined by the International Telecommunications Union has been in the form of a new set of standards. The Third Generation Partnership Project (3GPP) has recommended a new network scheme deemed ‘Long Term Evolution’ (LTE). Under the new standards, all communications in an LTE network are carried over an IP channel from user equipment (UE), such as a mobile phone or smartphone, to an all-IP core named the Evolved Packet Core (EPC). The EPC may then provide gateway access to other networks, while also ensuring an acceptable QoE for a user's network activity and properly charging the subscriber for such activity.
The 3GPP generally describes the components of the EPC and their interactions with each other for example, describing components such as a Policy and Charging Rules Function (PCRF), Policy and Charging Enforcement Function (PCEF), and Bearer Binding and Event Reporting Function (BBERF) of the EPC.